The 1,2,4-benzotriazine 1,4-dioxides are an important class of potential anticancer drugs that selectively kill the low-oxygen (hypoxic) cells found in solid tumors. These compounds undergo intracellular one-electron enzymatic reduction to yield an oxygen-sensitive drug radical intermediate that partitions forward, under hypoxic conditions, to generate a highly reactive secondary radical that c...

The ˙OH radical is released from 3-trifluoromethyl-quinoxaline 1,4-dioxides upon one-electron reduction by cytochrome P450 oxidoreductase. This process effectively competes with back oxidation of the intermediate radical anion by oxygen and underlies the increased aerobic cytotoxicity of such compounds compared to that seen for the related clinical bioreductive benzotriazine drug, tirapazamine.

An efficient approach for the assembly of 6H-benzo[f]cyclopenta[d][1,2]thiazepine 5,5-dioxides via a palladium-catalyzed tandem reaction of 2-(2-alkynyl)benzenesulfonamide with 2-alkynylvinyl bromide is reported. This transformation proceeds smoothly through a double carbopalladation with high efficiency.

ABSTRACT A series of 6'-chloro-1',1'-dioxospiro[4H-benzo[d][1,3,7]oxadiazocine-4,3'(2'H)-[1,4,2]benzodithiazine]-2,6(1H,5H)dione derivatives have been synthesized from isatoic anhydride and 3-(R2-amino)-1,4,2-benzodithiazine 1,1-dioxides. Some synthetic limitations are discussed on the basis of quantum chemical calculations performed by use of the Hartree-Fock method. GRAPHICAL ABSTRACT

An unexpected result from the reaction of 2-alkynylaryldiazonium tetrafluoroborate with sulfur dioxide is described. In the presence of morpholin-4-amine, this transformation catalyzed by copper(i) bromide proceeds through insertion of sulfur dioxide and intramolecular 5-endo cyclization, leading to benzo[b]thiophene 1,1-dioxides in moderate to good yields.

The incorporation of the (trifluoromethyl)thio group into the benzo[e][1,2]thiazine 1,1-dioxide scaffold via a reaction of trifluoromethanesulfanylamide with 2-(2-alkynyl)benzenesulfonamide is reported. The transformation proceeds under mild conditions to afford the 4-((trifluoromethyl)thio)-2H-benzo[e][1,2]thiazine 1,1-dioxides in moderate to good yields.

A series of 6-substituted 2-benzoxathiine-2,2-dioxides were synthesized starting from 2,5-dihydroxybenzaldehyde, and then screened in vitro for their inhibition properties against five human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms. All the compounds showed excellent selectivity against the mitochondrial (hCA VA) and the tumor associated (hCA IX and XII) enzymes.

10H-phenothiazines are prepared by Smiles rearrangement. These prepared phenothiazines are used as base to prepare ribofuranosides by treatment with β-Dribofuranosyl-1-acetate-2,3,5-tribenzoate. 10H-Phenothiazines on refluxing with hydrogen peroxide in glacial acetic acid gave 10H-phenothiazine-5,5-dioxides. Their antioxidant and antimicrobial activity have been carried out. The structure of th...